aquarist

An aquarist is a person who maintains aquatic organisms in aquariums, ranging from small home tanks to large public displays. The term covers hobbyists who keep freshwater, brackish, and marine species as well as professionals who design, stock, and maintain exhibition tanks in educational, commercial, or institutional settings.

Core activities include planning the tank layout, selecting compatible species, and managing water conditions such as temperature, pH, hardness, and chemical balance (ammonia, nitrite, nitrate, and, in saltwater systems, salinity). Equipment commonly used includes filtration, aeration, heaters, lighting, substrates, and, in planted or reef setups, CO2 systems and specialized lighting. Regular maintenance involves routine water changes, cleaning, testing, and monitoring behavior and health.

Health and welfare are central concerns. Quarantine of new arrivals helps prevent disease. Aquarists observe for signs of illness, provide appropriate nutrition, and rapidly address issues. Some pursue breeding to rear fry and improve genetic lines. Record-keeping on water parameters, feeding, and outcomes is common.

Ethics and sustainability are important aspects. Responsible aquarists avoid overstocking, minimize environmental impact, and prefer animals from reputable breeders or captive-bred sources. They often join clubs or associations and may work in public aquariums or educational programs.

Common specializations include freshwater hobbyists, brackish water keepers, and marine or reef aquarists who maintain complex saltwater ecosystems with corals and invertebrates. Aquarists may also engage in aquascaping, the art of arranging plants, rockwork, and creatures to create aesthetically pleasing habitats.